Engine lubricating oil generally comprises a base oil and additives. The base oil can be mineral oil (petroleum based oil), synthetic oil (non-petroleum based oil) or a blend of mineral and synthetic oils. The additives are chemical compounds added to the base oil to enhance the performance of the oil, and may include additives such as antioxidants, detergents, anti-wear agents, anti-rust agents and anti-foaming agents.
Lubricating oil degrades over time as the oil comes into contact with engine combustion byproducts and engine components. This degradation is the result of a number of physical phenomena. The additives become depleted. Foreign particles and soluble components mix with and contaminate the oil. The base oil molecules may react and combine to form heavier molecules, often causing the oil to darken and/or thicken. The oil molecules may undergo oxidation and nitration and may form acidic chemical compounds.
The type of engine oil, such as mineral, synthetic or blended (a.k.a. semi-synthetic), can have a significant effect on the formation and subsequent alteration of these chemical compounds. Additional factors such as ambient temperature, humidity, duty cycle and environmental conditions such as the presence of dust and dirt also play a role in the oil degradation process.
Currently, the condition of engine oil, i.e., when the useful life of the engine oil has ended, often is estimated by monitoring the length of time the oil has been in use or the distance travelled by the vehicle or machine, and modifying the estimate by taking into consideration the conditions under which the engine has been operating. The estimate is used to predict the interval, in time or mileage, between oil changes. However, the extent of engine oil degradation, i.e., the condition of the oil at any given time, may not be reliably detected by this method.
It would be useful to be able to detect the extent of oil degradation in used oil. The present disclosure addresses this need.
The present disclosure is directed toward a method of detecting the extent of oil degradation. Depending on the need, proactive action may be taken to avoid engine damage or failure.